T Monocerotis

T Monocerotis
Location of T Monocerotis (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Monoceros
Right ascension 06h 25m 13.00s
Declination +07° 05′ 08.6″
Apparent magnitude (V) 5.58–6.58
Characteristics
Evolutionary stage Supergiant + Main-sequence
Spectral type G3Iabv + A0p
Variable type δ Cep
Astrometry
Radial velocity (Rv)+48.8±9.1 km/s
Proper motion (μ) RA: +0.846 mas/yr
Dec.: −3.025 mas/yr
Parallax (π)0.533±0.066 mas
Distanceapprox. 6,100 ly
(approx. 1,900 pc)
Other designations
T Mon, BD+07 1273, HD 44990, HIP 30541, HR 2310, SAO 113845, TIC 206703838, TYC 145-875-1, IRAS 06225+0706, 2MASS J06251300+0705084
Database references
SIMBADdata

T Monocerotis (T Mon) is a classical Cepheid variable star in the constellation of Monoceros, visually located 2° northwest of Epsilon Monocerotis. Along with Eta Aquilae and X Sagittarii, it is one of the Cepheid variables considered easy to find in the night sky. It is located 1350 parsecs or 4400 light-years from the solar system. The brightness of T Monocerotis varies between apparent magnitude +5.58 and +6.62 over a period of 27.0247 days. This period has been increasing over time, being 27.0092 days before the year 1900.